tegra: Convert CONFIG_PWM_TEGRA to Kconfig

Move this option to Kconfig and clean up the header files. Adjust the only
user (the LCD driver) to work with the new driver.

Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Tom Warren <twarren@nvidia.com>
diff --git a/configs/nyan-big_defconfig b/configs/nyan-big_defconfig
index 12377bd..1243006 100644
--- a/configs/nyan-big_defconfig
+++ b/configs/nyan-big_defconfig
@@ -26,6 +26,7 @@
 CONFIG_DM_REGULATOR=y
 CONFIG_DM_REGULATOR_FIXED=y
 CONFIG_DM_PWM=y
+CONFIG_PWM_TEGRA=y
 CONFIG_SYS_NS16550=y
 CONFIG_TEGRA114_SPI=y
 CONFIG_TPM_TIS_INFINEON=y